Samuel Manda
Biographic Data
| ID | 3996113 |
|---|---|
| NAME | Samuel Manda |
| GIVEN NAMES | Samuel |
| FAMILY NAME | Manda |
| SIGNATURE | MANDA S |
| AFFILIATIONS | South African Medical Research Council |
| ORCID | 0000-0002-9672-3312 |
| VERIFIED | Yes |
| TOTAL WORKS | 23 |
| TOTAL CITATIONS | 25 |
| AUTHOR COUNT | 23 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1999 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 2 |
Identifying volunteer groups based on motivational patterns using latent class analysis
Background Volunteers dedicate their time and effort to enhancing communities, supporting social causes, and fostering social cohesion. Self-Determination Theory suggests that volunteer motivation may vary along a continuum of internalization from controlled to autonomous motivation. However, there is limited understanding of whether motivational profiles reflect qualitatively distinct types or primarily differ in intensity. This study seeks to i…
Global, regional, and national prevalence and determinants of volunteer work
Volunteering rates vary significantly by region and country, often correlating with individuals' educational levels. These findings are essential for policymakers aiming to enhance volunteer initiatives. By understanding the regional contexts and factors, such as the influence of education level on volunteering, policymakers can develop tailored programs that attract new volunteers and promote retention, ultimately fostering greater community eng…
Exploring the impact of a maternal support grant to improve mental health and food security amongst pregnant women in South Africa during the Covid‐19 pandemic
Social protection during pregnancy may support pregnant women struggling to meet basic needs to ensure a healthy pregnancy and buffer negative impacts of multiple adversities. We assessed the effect of a bimonthly digital food voucher, delivered to pregnant women during the COVID‐19 pandemic in the Cape Town area, on their mental health, hunger, and dietary diversity. Pregnant women from antenatal clinics in specific high‐poverty areas were invit…
Modeling the positive testing rate of Covid-19 in South Africa using a semi-parametric smoother for binomial data
Identification and isolation of COVID-19 infected persons plays a significant role in the control of COVID-19 pandemic. A country's COVID-19 positive testing rate is useful in understanding and monitoring the disease transmission and spread for the planning of intervention policy. Using publicly available data collected between March 5th, 2020 and May 31st, 2021, we proposed to estimate both the positive testing rate and its daily rate of change …
Seroprevalence survey of anti-Sars-CoV-2 antibody and associated factors in South Africa
Population-based serological testing is important to understand the epidemiology and estimate the true cumulative incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to inform public health interventions. This study reports findings of a national household population SARS-CoV-2 serosurvey in people 12 years and older in South Africa. This cross-sectional multi-stage random stratified cluster survey undertaken from November 2…
Inter-Country Covid-19 Contagiousness Variation in Eight African Countries
The estimates of contiguousness parameters of an epidemic have been used for health-related policy and control measures such as non-pharmaceutical control interventions (NPIs). The estimates have varied by demographics, epidemic phase, and geographical region. Our aim was to estimate four contagiousness parameters: basic reproduction number ( R 0 ), contact rate, removal rate, and infectious period of coronavirus disease 2019 (COVID-19) among eig…
Accounting for Sampling Weights in the Analysis of Spatial Distributions of Disease Using Health Survey Data, with an Application to Mapping Child Health in Malawi and Mozambique
Most analyses of spatial patterns of disease risk using health survey data fail to adequately account for the complex survey designs. Particularly, the survey sampling weights are often ignored in the analyses. Thus, the estimated spatial distribution of disease risk could be biased and may lead to erroneous policy decisions. This paper aimed to present recent statistical advances in disease-mapping methods that incorporate survey sampling in the…
Spatial Co-Morbidity of Childhood Acute Respiratory Infection, Diarrhoea and Stunting in Nigeria
In low- and middle-income countries, children aged below 5 years frequently suffer from disease co-occurrence. This study assessed whether the co-occurrence of acute respiratory infection (ARI), diarrhoea and stunting observed at the child level could also be reflected ecologically. We considered disease data on 69,579 children (0-59 months) from the 2008, 2013, and 2018 Nigeria Demographic and Health Surveys using a hierarchical Bayesian spatial…
Estimating Unhealthy Food Effects on Childhood Overweight in Malawi Using an Observational Study
Optimising geographical accessibility to primary health care
Background Little is known about the contribution of community health posts and community health workers (CHWs) to geographical accessibility of primary healthcare (PHC) services at community level and strategies for optimising geographical accessibility to these services. Methods Using a complete georeferenced census of community health posts and CHWs in Niger and other high-resolution spatial datasets, we modelled travel times to community heal…
A Comparison of Bayesian Spatial Models for HIV Mapping in South Africa
Despite making significant progress in tackling its HIV epidemic, South Africa, with 7.7 million people living with HIV, still has the biggest HIV epidemic in the world. The Government, in collaboration with developmental partners and agencies, has been strengthening its responses to the HIV epidemic to better target the delivery of HIV care, treatment strategies and prevention services. Population-based household HIV surveys have, over time, con…
A Spatial Analysis of Tuberculosis Related Mortality in South Africa
Background: South Africa, with an estimated annual tuberculosis (TB) incidence of 360,000 cases in 2019, remains one of the countries with the largest burden of TB in the world. The identification of highly burdened TB areas could support public health policy planners to optimally target resources and TB control and prevention interventions. Objective: To investigate the spatial epidemiology and distribution of TB mortality in South Africa in 201…
A Spatial Analysis of Covid-19 in African Countries
The ongoing highly contagious coronavirus disease 2019 (COVID-19) pandemic, which started in Wuhan, China, in December 2019, has now become a global public health problem. Using publicly available data from the COVID-19 data repository of Our World in Data, we aimed to investigate the influences of spatial socio-economic vulnerabilities and neighbourliness on the COVID-19 burden in African countries. We analyzed the first wave (January-September …
Spatial Co-Clustering of Cardiovascular Diseases and Select Risk Factors among Adults in South Africa
Background: Cardiovascular diseases (CVDs) are part of the leading causes of mortality and morbidity in developing countries, including South Africa, where they are a major public health issue. Understanding the joint spatial clustering of CVDs and associated risk factors to determine areas in need of enhanced integrated interventions would help develop targeted, cost-effective and productive mediations. We estimated joint spatial associations an…
Assessing the effects of maternal HIV infection on pregnancy outcomes using cross-sectional data in Malawi
The study has found that maternal HIV infection had an adverse effect on birth weight and perinatal mortality in 2010. Birth weight was not dependent on ART uptake but perinatal mortality was higher among infants of HIV-infected mothers who were not on ART. The higher birth weight among HIV-infected mothers and similarity in perinatal mortality with HIV-uninfected mothers in 2015-16 may be indicative of successes of interventions within the PMTCT…
Smoothed Temporal Atlases of Age-Gender All-Cause Mortality in South Africa
Most mortality maps in South Africa and most contried of the sub-Saharan region are static, showing aggregated count data over years or at specific years. Lack of space and temporral dynamanics in these maps may adversely impact on their use and application for vigorous public health policy decisions and interventions. This study aims at describing and modeling sub-national distributions of age-gender specific all-cause mortality and their tempor…
Predictors of survival among HIV-positive children on ART in Swaziland
The objective of the study was to determine predictors of survival among HIV-positive children (<15 years) in Swaziland. A retrospective cohort analysis of medical records for 4 167 children living with HIV who were initiated on antiretroviral therapy (ART) between 2004 and 2008, and followed up until 2014 was conducted in clinical settings at 36 health facilities. The Kaplan Meier Estimator, signed-ranks test, and the Cox proportional hazards re…
Reduction in child mortality in Ethiopia
BACKGROUND: To examine changes in under-5 mortality, coverage of child survival interventions and nutritional status of children in Ethiopia between 2000 and 2011. Using the Lives Saved Tool, the impact of changes in coverage of child survival interventions on under-5 lives saved was estimated. METHODS: Estimates of child mortality were generated using three Ethiopia Demographic and Health Surveys undertaken between 2000 and 2011. Coverage indica…
Does adjusting for recall in trend analysis affect coverage estimates for maternal and child health indicators? An analysis of DHS and Mics survey data
BackgroundThe Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) are the major data sources in low- and middle-income countries (LMICs) for evaluating health service coverage. For certain maternal and child health (MCH) indicators, the two surveys use different recall periods: 5 years for DHS and 2 years for MICS.ObjectiveWe explored whether the different recall periods for DHS and MICS affect coverage trend analys…
Assessment of Malawi’s success in child mortality reduction through the lens of the Catalytic Initiative Integrated Health Systems Strengthening programme
BACKGROUND: Malawi is estimated to have achieved its Millennium Development Goal (MDG) 4 target. This paper explores factors influencing progress in child survival in Malawi including coverage of interventions and the role of key national policies. METHODS: We performed a retrospective evaluation of the Catalytic Initiative (CI) programme of support (2007-2013). We developed estimates of child mortality using four population household surveys und…
Assessment of settlement models for engagement of communities in forest land under claim in Jessievale and Roburna communities in Mpumalanga, South Africa
Livelihoods, land use and land cover change in the Zambezi Region, Namibia
Birth intervals, breastfeeding and determinants of childhood mortality in Malawi
Birth intervals, breastfeeding and determinants of childhood mortality in Malawi
Assessment of settlement models for engagement of communities in forest land under claim in Jessievale and Roburna communities in Mpumalanga, South Africa
Global, regional, and national prevalence and determinants of volunteer work
Volunteering rates vary significantly by region and country, often correlating with individuals' educational levels. These findings are essential for policymakers aiming to enhance volunteer initiatives. By understanding the regional contexts and factors, such as the influence of education level on volunteering, policymakers can develop tailored programs that attract new volunteers and promote retention, ultimately fostering greater community eng…
Birth intervals, breastfeeding and determinants of childhood mortality in Malawi
Assessment of Malawi’s success in child mortality reduction through the lens of the Catalytic Initiative Integrated Health Systems Strengthening programme
BACKGROUND: Malawi is estimated to have achieved its Millennium Development Goal (MDG) 4 target. This paper explores factors influencing progress in child survival in Malawi including coverage of interventions and the role of key national policies. METHODS: We performed a retrospective evaluation of the Catalytic Initiative (CI) programme of support (2007-2013). We developed estimates of child mortality using four population household surveys und…
Assessment of settlement models for engagement of communities in forest land under claim in Jessievale and Roburna communities in Mpumalanga, South Africa
Livelihoods, land use and land cover change in the Zambezi Region, Namibia
Reduction in child mortality in Ethiopia
BACKGROUND: To examine changes in under-5 mortality, coverage of child survival interventions and nutritional status of children in Ethiopia between 2000 and 2011. Using the Lives Saved Tool, the impact of changes in coverage of child survival interventions on under-5 lives saved was estimated. METHODS: Estimates of child mortality were generated using three Ethiopia Demographic and Health Surveys undertaken between 2000 and 2011. Coverage indica…
Does adjusting for recall in trend analysis affect coverage estimates for maternal and child health indicators? An analysis of DHS and Mics survey data
BackgroundThe Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) are the major data sources in low- and middle-income countries (LMICs) for evaluating health service coverage. For certain maternal and child health (MCH) indicators, the two surveys use different recall periods: 5 years for DHS and 2 years for MICS.ObjectiveWe explored whether the different recall periods for DHS and MICS affect coverage trend analys…
Smoothed Temporal Atlases of Age-Gender All-Cause Mortality in South Africa
Most mortality maps in South Africa and most contried of the sub-Saharan region are static, showing aggregated count data over years or at specific years. Lack of space and temporral dynamanics in these maps may adversely impact on their use and application for vigorous public health policy decisions and interventions. This study aims at describing and modeling sub-national distributions of age-gender specific all-cause mortality and their tempor…
Predictors of survival among HIV-positive children on ART in Swaziland
The objective of the study was to determine predictors of survival among HIV-positive children (<15 years) in Swaziland. A retrospective cohort analysis of medical records for 4 167 children living with HIV who were initiated on antiretroviral therapy (ART) between 2004 and 2008, and followed up until 2014 was conducted in clinical settings at 36 health facilities. The Kaplan Meier Estimator, signed-ranks test, and the Cox proportional hazards re…
Spatial Co-Clustering of Cardiovascular Diseases and Select Risk Factors among Adults in South Africa
Background: Cardiovascular diseases (CVDs) are part of the leading causes of mortality and morbidity in developing countries, including South Africa, where they are a major public health issue. Understanding the joint spatial clustering of CVDs and associated risk factors to determine areas in need of enhanced integrated interventions would help develop targeted, cost-effective and productive mediations. We estimated joint spatial associations an…
Assessing the effects of maternal HIV infection on pregnancy outcomes using cross-sectional data in Malawi
The study has found that maternal HIV infection had an adverse effect on birth weight and perinatal mortality in 2010. Birth weight was not dependent on ART uptake but perinatal mortality was higher among infants of HIV-infected mothers who were not on ART. The higher birth weight among HIV-infected mothers and similarity in perinatal mortality with HIV-uninfected mothers in 2015-16 may be indicative of successes of interventions within the PMTCT…
Optimising geographical accessibility to primary health care
Background Little is known about the contribution of community health posts and community health workers (CHWs) to geographical accessibility of primary healthcare (PHC) services at community level and strategies for optimising geographical accessibility to these services. Methods Using a complete georeferenced census of community health posts and CHWs in Niger and other high-resolution spatial datasets, we modelled travel times to community heal…
A Comparison of Bayesian Spatial Models for HIV Mapping in South Africa
Despite making significant progress in tackling its HIV epidemic, South Africa, with 7.7 million people living with HIV, still has the biggest HIV epidemic in the world. The Government, in collaboration with developmental partners and agencies, has been strengthening its responses to the HIV epidemic to better target the delivery of HIV care, treatment strategies and prevention services. Population-based household HIV surveys have, over time, con…
A Spatial Analysis of Tuberculosis Related Mortality in South Africa
Background: South Africa, with an estimated annual tuberculosis (TB) incidence of 360,000 cases in 2019, remains one of the countries with the largest burden of TB in the world. The identification of highly burdened TB areas could support public health policy planners to optimally target resources and TB control and prevention interventions. Objective: To investigate the spatial epidemiology and distribution of TB mortality in South Africa in 201…
A Spatial Analysis of Covid-19 in African Countries
The ongoing highly contagious coronavirus disease 2019 (COVID-19) pandemic, which started in Wuhan, China, in December 2019, has now become a global public health problem. Using publicly available data from the COVID-19 data repository of Our World in Data, we aimed to investigate the influences of spatial socio-economic vulnerabilities and neighbourliness on the COVID-19 burden in African countries. We analyzed the first wave (January-September …
Inter-Country Covid-19 Contagiousness Variation in Eight African Countries
The estimates of contiguousness parameters of an epidemic have been used for health-related policy and control measures such as non-pharmaceutical control interventions (NPIs). The estimates have varied by demographics, epidemic phase, and geographical region. Our aim was to estimate four contagiousness parameters: basic reproduction number ( R 0 ), contact rate, removal rate, and infectious period of coronavirus disease 2019 (COVID-19) among eig…
Accounting for Sampling Weights in the Analysis of Spatial Distributions of Disease Using Health Survey Data, with an Application to Mapping Child Health in Malawi and Mozambique
Most analyses of spatial patterns of disease risk using health survey data fail to adequately account for the complex survey designs. Particularly, the survey sampling weights are often ignored in the analyses. Thus, the estimated spatial distribution of disease risk could be biased and may lead to erroneous policy decisions. This paper aimed to present recent statistical advances in disease-mapping methods that incorporate survey sampling in the…
Spatial Co-Morbidity of Childhood Acute Respiratory Infection, Diarrhoea and Stunting in Nigeria
In low- and middle-income countries, children aged below 5 years frequently suffer from disease co-occurrence. This study assessed whether the co-occurrence of acute respiratory infection (ARI), diarrhoea and stunting observed at the child level could also be reflected ecologically. We considered disease data on 69,579 children (0-59 months) from the 2008, 2013, and 2018 Nigeria Demographic and Health Surveys using a hierarchical Bayesian spatial…
Estimating Unhealthy Food Effects on Childhood Overweight in Malawi Using an Observational Study
Modeling the positive testing rate of Covid-19 in South Africa using a semi-parametric smoother for binomial data
Identification and isolation of COVID-19 infected persons plays a significant role in the control of COVID-19 pandemic. A country's COVID-19 positive testing rate is useful in understanding and monitoring the disease transmission and spread for the planning of intervention policy. Using publicly available data collected between March 5th, 2020 and May 31st, 2021, we proposed to estimate both the positive testing rate and its daily rate of change …
Seroprevalence survey of anti-Sars-CoV-2 antibody and associated factors in South Africa
Population-based serological testing is important to understand the epidemiology and estimate the true cumulative incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to inform public health interventions. This study reports findings of a national household population SARS-CoV-2 serosurvey in people 12 years and older in South Africa. This cross-sectional multi-stage random stratified cluster survey undertaken from November 2…
Exploring the impact of a maternal support grant to improve mental health and food security amongst pregnant women in South Africa during the Covid‐19 pandemic
Social protection during pregnancy may support pregnant women struggling to meet basic needs to ensure a healthy pregnancy and buffer negative impacts of multiple adversities. We assessed the effect of a bimonthly digital food voucher, delivered to pregnant women during the COVID‐19 pandemic in the Cape Town area, on their mental health, hunger, and dietary diversity. Pregnant women from antenatal clinics in specific high‐poverty areas were invit…
Global, regional, and national prevalence and determinants of volunteer work
Volunteering rates vary significantly by region and country, often correlating with individuals' educational levels. These findings are essential for policymakers aiming to enhance volunteer initiatives. By understanding the regional contexts and factors, such as the influence of education level on volunteering, policymakers can develop tailored programs that attract new volunteers and promote retention, ultimately fostering greater community eng…
Identifying volunteer groups based on motivational patterns using latent class analysis
Background Volunteers dedicate their time and effort to enhancing communities, supporting social causes, and fostering social cohesion. Self-Determination Theory suggests that volunteer motivation may vary along a continuum of internalization from controlled to autonomous motivation. However, there is limited understanding of whether motivational profiles reflect qualitatively distinct types or primarily differ in intensity. This study seeks to i…
Medicine (20 works) · Environmental health (16 works) · Demography (14 works) · Geography (14 works) · Population (11 works) · Demography (10 works) · Global Maternal and Child Health (8 works) · Child Nutrition and Water Access (6 works) · Pediatrics (6 works) · Psychological intervention (6 works)